With an advancement of multifarious electronic equipment toward diversification and multifunction in late years, operating switches of multi-directional type, which combine a pushing manipulation and tilting manipulation, are increasingly being utilized.
A multi-directional operating switch of the prior art is described hereinafter by referring to FIG. 5 through FIG. 7.
FIG. 5 is a cross-sectional view showing the multi-directional operating switch of the prior art in a neutral position wherein no pushing manipulation is being made. In the figure, an insulation substrate 1 employs plural pairs of stationary contacts 2A, 2B, 2C, (and others not shown) on its upper surface, and an elastic contactor body 3 made of elastic rubber is disposed on the insulation substrate 1. The elastic contactor body 3 is formed at its center and a right, a left, a front and a rear sides with a plurality of domed portions 3A, 3B, 3C, (and others not shown, of which lower surfaces are provided with movable contacts 4A, 4B, 4C, (and others not shown) each facing against the stationary contacts 2A, 2B and 2C.
Also, the multi-directional operating switch of the prior art is equipped with a manipulation body 5 made of an insulating polymeric resin and a case 6 to cover the manipulation body 5 and the elastic contactor body 3. A protuberant part 5A at a lower center surface of the manipulation body 5 is inserted into a hole 3F in an upper center surface of the elastic contactor body 3. The manipulation body 5 is provided with depressing limbs 5B, 5C, (and others not shown) at the right, the left, the front and the rear sides of its lower surface above the domed portions 3B and 3C. A top center part 5F of the manipulation body 5 that protrudes from an opening 6A of the case 6 is attached with a discus-shaped knob 7, and a semispherical center area 5G at an upper surface of the manipulation body 5 is thrust upwardly by an elastic restorative force of the domed portion 3A to contact elastically against a lower peripheral surface of the opening 6A in the case 6.
In the above structure, when the knob 7 is subjected to a pushing manipulation by being pressed vertically downward from its neutral position in FIG. 5, the center area 5G of the manipulation body 5 departs from the lower peripheral surface of the opening 6A of the case 6 as shown in FIG. 6, and the protuberant part 5A inserted into the hole 3F in the elastic contactor body 3 depresses the domed portion 3A. The depressed domed portion 3A moves downward to cause the movable contact 4A at its lower surface to contact with the stationary contacts 2A, thereby making an electrical connection of the stationary contacts 2A. Subsequently, when a pushing force of the manipulation to the knob 7 is removed, the movable contact 4A at the lower surface separates from the stationary contacts 2A to disconnect them by the elastic restorative force of the domed portion 3A, and the manipulation body 5 and the knob 7 return to their original neutral positions as shown in FIG. 5.
Also, when a left edge of the knob 7 is subjected to a tilting manipulation by being pressed toward the left as shown in FIG. 7 from its neutral position in FIG. 5, the manipulation body 5 tilts toward the left with a tip of the protuberant part 5A as being a fulcrum while the semispherical center area 5G slides along the lower peripheral surface of the opening 6A of the case 6 as they maintain an elastic contact with each other, and a depressing limb 5B at a lower left end depresses a domed portion 3B. The depressed domed portion 3B moves downward to cause the movable contact 4B at its lower surface to contact with the stationary contacts 2B, thereby making an electrical connection of the stationary contacts 2B. And, when a force of the tilting manipulation to the left edge of the knob 7 is removed, the movable contact 4B at the lower surface separates from the stationary contacts 2B by the elastic restorative force of the domed portions 3B, and the manipulation body 5 and the knob 7 return to their original neutral positions in FIG. 5.
In the same manner as above, if the knob 7 is manipulated for tilting it either rightward, forward or backward from the neutral position of FIG. 5, the manipulation body 5 tilts rightward, forward or backward direction, and a depressing limb 5C at the lower surface depresses a domed portion 3C, 3D or 3E. The depressed domed portion 3C moves downward to make electrical connection of the stationary contacts 2C by a corresponding movable contact 4C at the lower surface respectively.
With the multi-directional operating switch of the prior art, however, there is a problem of causing a scraping feeling with regard to manipulatory feeling of the switch due to friction of the semispherical center area 5G at the upper surface of the manipulation body 5, since the semispherical center area 5G, which is thrust upwardly by the domed portions 3A at the center, slides elastically along the lower peripheral surface of the opening 6A of the case 6 when the knob 7 is subjected to the tilting manipulation rightward, leftward, forward or backward, or when it is returned to the neutral position.